Wireless Memory Device Authentication

1. A wireless memory device comprising: a memory unit; and at least one processor configured to: receive a challenge comprising a plurality of bits from a communications device; and in an instance where the challenge is a first challenge from the communications device: form a signature comprising a plurality of numbers from a public key and a private key based on the challenge by looking up the challenge in a table and, for each bit of the plurality of bits of the challenge, forming the signature from either a first or second number of a pair of numbers in accordance with a value of the respective bit of the challenge, wherein a plurality of pairs of public and private keys are stored by the memory unit and each pair of the plurality of pairs of the public key and the private key are used only once to form the signature and never sent out or copied from the memory unit; cause the signature to be sent to the communications device; receive a key stream from the communications device; and destroy the private key, wherein the signature was formed with a private key associated with each bit of the plurality of bits of the challenge; and the private key further comprises a pair of random numbers in accordance with a value of a respective bit of the plurality of bits of the challenge; and in an instance where the challenge is not the first challenge from the communications device: cause at least a portion of the key stream to be sent to the communications device to make certain that the wireless memory device is authenticated.

2. The wireless memory device of claim 1 , wherein the at least one processor is further configured to form the signature using a Lamport signature scheme.

3. The wireless memory device of claim 1 , wherein the memory unit comprises at least one pre-stored certified public key and at least one pre-stored private key.

4. The device of claim 1 , wherein the wireless memory device comprises a radio frequency memory tag.

5. A method comprising: receiving a challenge comprising a plurality of bits from a communications device; and in an instance where the challenge is a first challenge from the communications device: forming a signature comprising a plurality of numbers from a public key and a private key based on the challenge by looking up the challenge in a table and, for each bit of the plurality of bits of the challenge, forming the signature from either a first or second number of a pair of numbers in accordance with a value of the respective bit of the challenge, wherein a plurality of pairs of public and private keys are stored by a memory unit and each pair of the plurality of pairs of the public key and the private key are used only once to form the signature and never sent out or copied from the memory unit; causing the signature to be sent to the communications device; receive a key stream from the communications device; and destroying the private key, wherein the signature was formed with a private key associated with each bit of the plurality of bits of the challenge; and the private key further comprises a pair of random numbers in accordance with a value of a respective bit of the plurality of bits of the challenge; and in an instance where the challenge is not the first challenge from the communications device: causing at least a portion of the key stream to be sent to the communications device.

6. The method of claim 5 wherein receiving a challenge is carried out by a wireless memory device comprising a memory unit and at least one processor, wherein the memory unit comprises at least one pre-stored certified public key and at least one pre-stored private key.

7. The method of claim 5 further comprising forming the signature using a Lamport signature scheme.

8. An apparatus, comprising: at least one processor and at least one memory including a computer program code, wherein the at least one memory including the computer program code is configured, with the at least one processor, at least to: receive a challenge comprising a plurality of bits from a communications device; and in an instance where the challenge is a first challenge from the communications device: form a signature comprising a plurality of numbers from a public key and a private key based on the challenge by looking up the challenge in a table and, for each bit of the plurality of bits of the challenge, forming the signature from either a first or second number of a pair of numbers in accordance with a value of the respective bit of the plurality of bits of the challenge, wherein a plurality of pairs of public and private keys are stored on a memory unit and each pair of the plurality of pairs of the public key and the private key are used only once to form the signature and never sent out or copied from the memory unit; cause the signature to be sent to the communications device; receive a key stream from the communications device; and destroy the private key, wherein the signature was formed with a private key associated with each bit of the plurality of bits of the challenge; and the private key further comprises a pair of random numbers in accordance with a value of a respective bit of the plurality of bits of the challenge; and in an instance where the challenge is not the first challenge from the communications device: cause at least a portion of the key stream to be sent to the communications device to make certain the wireless memory device is authenticated.

9. The apparatus of claim 8 , wherein the at least one memory comprises at least one pre-stored certified public key and at least one pre-stored private key.

10. The apparatus of claim 8 , wherein the at least one memory including the computer program code is further configured to, with the at least one processor, cause the apparatus to form the signature using a Lamport signature scheme.

11. A computer program product comprising: at least one non-transitory computer-readable storage medium having computer-readable program instructions stored therein with the computer-readable program instructions comprising program instructions configured to: receive a challenge comprising a plurality of bits from a communications device; and in an instance where the challenge is a first challenge from the communications device: form a signature comprising a plurality of numbers from a public key and a private key based on the challenge by looking up the challenge in a table and, for each bit of the plurality of bits of the challenge, forming the signature from either a first or second number of a pair of numbers in accordance with a value of the respective bit of the plurality of bits of the challenge, wherein a plurality of pairs of public and private keys are stored on a memory unit and each pair of the plurality of pairs of the public key and the private key are used only once to form the signature and never sent out or copied from the memory unit; cause the signature to be sent to the communications device; receive a key stream from the communications device; and destroy the private key, wherein the signature was formed with a private key associated with each bit of the plurality of bits of the challenge; and the private key further comprises a pair of random numbers in accordance with a value of a respective bit of the plurality of bits of the challenge; and in an instance where the challenge is not the first challenge from the communications device: cause at least a portion of the key stream to be sent to the communications device.

12. A computer program product according to claim 11 further comprises program code which when executed by an apparatus causes the apparatus at least to receive a key stream from the communications device.

13. A computer program product according to claim 11 further comprises program code which when executed by an apparatus causes the apparatus at least to form the signature using a Lamport signature scheme.

14. A method comprising: receiving a challenge comprising a plurality of bits from a communications device; and in an instance where the challenge is a first challenge from the communications device: forming a signature comprising a plurality of numbers from a public key and a private key based on the challenge by looking up the challenge in a table and, for each bit of the plurality of bits of the challenge, forming the signature from either a first or second number of a pair of numbers in accordance with a value of the respective bit of the plurality of bits of the challenge, wherein a plurality of pairs of public and private keys are stored by a memory unit and each pair of the plurality of pairs of the public key and the private key are used only once to form the signature and never sent out or copied from the memory unit; causing the signature to be sent to the communications device; and receiving a key stream from the communications device; and in an instance where the challenge is not a first challenge from the communications device: causing at least a portion of the key stream to be sent to the communications device to make certain that communications with the communications device is authenticated.

15. The method of claim 14 , wherein the signature is formed using a Lamport signature scheme.

16. The method of claim 15 , wherein the key stream contains a time stamp in order to limit a validity of authentication to one or more of a particular duration of time after the time stamp, a particular day, or a particular time of day.

17. The method of claim 15 , further comprising: receiving an authentication key from the communications device, the authentication key comprising a time stamp in order to limit a validity of authentication to a certain time of day; and causing communication with the communications device.